Electrolytic capacitors are typically provided with a metal encasement for enclosing an anode, cathode, liquid electrolyte and a separator material positioned between the anode and cathode. The metal encasement is provided with feedthroughs through which the anode and cathode leads extend to facilitate electrical connection to other circuit components. The encasement also includes a fill port to accommodate filling the capacitor with a liquid electrolyte. The encasement typically includes a case and a cover that is welded to the case to hermetically seal the capacitor.
Electronic devices, particularly implantable medical devices, are becoming physically smaller, often with increased functionality. Accordingly, it is desirable to reduce the internal space required for capacitors included in such devices.
Some degree of packaging inefficiency is generally associated with a metal encasement. The metal encasement may not conform to the space available for the capacitor formed by the contours of the electronic device housing and other internal components. Additional features of the encasement such as the feedthroughs and fill port can require additional space and a minimum encasement thickness. A header space is often provided to accommodate additional features as well as facilitate welding of the cover to the case.